POTATO 269 



barrel, pour in the solution of corrosive sublimate and 

 allow it to stand two or three hours, with frequent stir- 

 rings in order to have the solution uniform. Select pota- 

 toes nearly free from scab as can be obtained ; put the seed 

 potatoes into bags, either before or after cutting them; 

 then dip them into the corrosive sublimate solution 

 and allow them to stay in for an hour and a half. If 

 seed potatoes are treated in this way and then planted on 

 land free from scab, the resultant crop will seldom be 

 seriously injured by scab. The expense of this treatment 

 including labor, should not exceed one dollar per acre, 

 as the material may be used repeatedly. But the treat- 

 ed potatoes should never be fed to animals, as corrosive 

 sublimate is a deadly poison. 



Formalin Treatment. This material should be mixed 

 with water at the rate of eight ounces (one half pint) of 

 commercial formalin to fifteen ga'llons of water. The 

 potatoes should be soaked two hours in it. If this method 

 is used the seed should be planted within two or three 

 days after treatment. This material gives equally as 

 good results as corrosive sublimate. It is slightly more 

 expensive, but the expense is light in any case. It has, 

 however, great advantages over the latter in that it is 

 not poisonous and, being a liquid, is easily diluted for use 

 and may be used in almost any kind of receptacle. This 

 material does not in any way injure the tubers or make 

 them dangerously poisonous. One pound of formalin, 

 costing not more than fifty cents, will make thirty gallons 

 of the disinfecting solution and is enough to treat fifty 

 bushels of potatoes. If the solution stands a long time 

 it will probably lose strength. 



Exposing to Light. If the tubers are exposed to the 

 full sunlight for several weeks before planting, the scab 



